diff options
Diffstat (limited to 'arch/x86/platform/olpc/olpc_dt.c')
| -rw-r--r-- | arch/x86/platform/olpc/olpc_dt.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c new file mode 100644 index 00000000000..dab87464753 --- /dev/null +++ b/arch/x86/platform/olpc/olpc_dt.c @@ -0,0 +1,183 @@ +/* + * OLPC-specific OFW device tree support code. + * + * Paul Mackerras August 1996. + * Copyright (C) 1996-2005 Paul Mackerras. + * + * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. + * {engebret|bergner}@us.ibm.com + * + * Adapted for sparc by David S. Miller davem@davemloft.net + * Adapted for x86/OLPC by Andres Salomon <dilinger@queued.net> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/bootmem.h> +#include <linux/of.h> +#include <linux/of_pdt.h> +#include <asm/olpc_ofw.h> + +static phandle __init olpc_dt_getsibling(phandle node) +{ + const void *args[] = { (void *)node }; + void *res[] = { &node }; + + if ((s32)node == -1) + return 0; + + if (olpc_ofw("peer", args, res) || (s32)node == -1) + return 0; + + return node; +} + +static phandle __init olpc_dt_getchild(phandle node) +{ + const void *args[] = { (void *)node }; + void *res[] = { &node }; + + if ((s32)node == -1) + return 0; + + if (olpc_ofw("child", args, res) || (s32)node == -1) { + pr_err("PROM: %s: fetching child failed!\n", __func__); + return 0; + } + + return node; +} + +static int __init olpc_dt_getproplen(phandle node, const char *prop) +{ + const void *args[] = { (void *)node, prop }; + int len; + void *res[] = { &len }; + + if ((s32)node == -1) + return -1; + + if (olpc_ofw("getproplen", args, res)) { + pr_err("PROM: %s: getproplen failed!\n", __func__); + return -1; + } + + return len; +} + +static int __init olpc_dt_getproperty(phandle node, const char *prop, + char *buf, int bufsize) +{ + int plen; + + plen = olpc_dt_getproplen(node, prop); + if (plen > bufsize || plen < 1) { + return -1; + } else { + const void *args[] = { (void *)node, prop, buf, (void *)plen }; + void *res[] = { &plen }; + + if (olpc_ofw("getprop", args, res)) { + pr_err("PROM: %s: getprop failed!\n", __func__); + return -1; + } + } + + return plen; +} + +static int __init olpc_dt_nextprop(phandle node, char *prev, char *buf) +{ + const void *args[] = { (void *)node, prev, buf }; + int success; + void *res[] = { &success }; + + buf[0] = '\0'; + + if ((s32)node == -1) + return -1; + + if (olpc_ofw("nextprop", args, res) || success != 1) + return -1; + + return 0; +} + +static int __init olpc_dt_pkg2path(phandle node, char *buf, + const int buflen, int *len) +{ + const void *args[] = { (void *)node, buf, (void *)buflen }; + void *res[] = { len }; + + if ((s32)node == -1) + return -1; + + if (olpc_ofw("package-to-path", args, res) || *len < 1) + return -1; + + return 0; +} + +static unsigned int prom_early_allocated __initdata; + +void * __init prom_early_alloc(unsigned long size) +{ + static u8 *mem; + static size_t free_mem; + void *res; + + if (free_mem < size) { + const size_t chunk_size = max(PAGE_SIZE, size); + + /* + * To mimimize the number of allocations, grab at least + * PAGE_SIZE of memory (that's an arbitrary choice that's + * fast enough on the platforms we care about while minimizing + * wasted bootmem) and hand off chunks of it to callers. + */ + res = alloc_bootmem(chunk_size); + if (!res) + return NULL; + prom_early_allocated += chunk_size; + memset(res, 0, chunk_size); + free_mem = chunk_size; + mem = res; + } + + /* allocate from the local cache */ + free_mem -= size; + res = mem; + mem += size; + return res; +} + +static struct of_pdt_ops prom_olpc_ops __initdata = { + .nextprop = olpc_dt_nextprop, + .getproplen = olpc_dt_getproplen, + .getproperty = olpc_dt_getproperty, + .getchild = olpc_dt_getchild, + .getsibling = olpc_dt_getsibling, + .pkg2path = olpc_dt_pkg2path, +}; + +void __init olpc_dt_build_devicetree(void) +{ + phandle root; + + if (!olpc_ofw_is_installed()) + return; + + root = olpc_dt_getsibling(0); + if (!root) { + pr_err("PROM: unable to get root node from OFW!\n"); + return; + } + of_pdt_build_devicetree(root, &prom_olpc_ops); + + pr_info("PROM DT: Built device tree with %u bytes of memory.\n", + prom_early_allocated); +} |